Large T antigen is a 708-residue protein from Simian virus 40. This is its AlphaFold structure prediction, created 3 Jul 2025. UniProt accession: P03070.
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The mean pLDDT of this model is 81.7 (confident overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.
| pLDDT band | Meaning | Share of residues |
|---|---|---|
| Above 90 | Very high: backbone and side chains are usually accurate | 65% |
| 70 to 90 | Confident: backbone generally right | 13% |
| 50 to 70 | Low: treat with caution | 4% |
| Below 50 | Very low: often disordered regions | 17% |
What pLDDT means and how to read it
Isoform large T antigen is a key early protein essential for both driving viral replication and inducing cellular transformation. Plays a role in viral genome replication by driving entry of quiescent cells into the cell cycle and by autoregulating the synthesis of viral early mRNA. Displays highly oncogenic activities by corrupting the host cellular checkpoint mechanisms that guard cell division and the transcription, replication, and repair of DNA. Participates in the modulation of cellular gene expression preceeding viral DNA replication. This step involves binding to host key cell cycle regulators retinoblastoma protein RB1/pRb and TP53. Induces the disassembly of host E2F1…
Isoform large T antigen forms homohexamers in the presence of ATP. Interacts with host HDAC1. Interacts (via LXCXE domain) with host RB1; the interaction induces the aberrant dissociation of RB1-E2F1 complex thereby disrupting RB1's activity. Interacts (via LXCXE domain) with host pRB-related proteins RBL1 and RBL2. Interacts (via C-terminus) with host TOP1 and POLA1 allowing DNA replication.…
Host nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 2FUF | X-ray | 1.45 Å | A=131-260 |
| 2IPR | X-ray | 1.5 Å | A/B=131-259 |
| 3QK2 | X-ray | 1.64 Å | A=131-260 |
| 2ITL | X-ray | 1.65 Å | A/B=131-259 |
| 3QN2 | X-ray | 1.66 Å | A=131-260 |
| 5D9I | X-ray | 1.7 Å | A/B=131-260 |
| 4RXH | X-ray | 1.76 Å | A/C=125-132 |
| 1SVM | X-ray | 1.94 Å | A/B/C/D/E/F=251-627 |
| 1SVL | X-ray | 1.95 Å | A/B/C=251-627 |
| 1Q1S | X-ray | 2.3 Å | A/B=110-133 |
| 2NL8 | X-ray | 2.3 Å | A=131-259 |
| 2NTC | X-ray | 2.4 Å | A/B=131-260 |
| 1Q1T | X-ray | 2.5 Å | A/B=110-134 |
| 2ITJ | X-ray | 2.5 Å | A/B=131-259 |
| 2IF9 | X-ray | 2.59 Å | A/B=131-260 |
| 1SVO | X-ray | 2.6 Å | A/B=251-627 |
| 1EJL | X-ray | 2.8 Å | A/B=126-132 |
| 1N25 | X-ray | 2.8 Å | A/B=260-627 |
| 4GDF | X-ray | 2.8 Å | A/B/E/F=131-627 |
| 9F3T | EM | 3.0 Å | A/B/C/D/E/F=266-627 |
Showing 20 of 48 experimental structures (best resolution first).
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